This was my first stay in B&B type place but I am very satisfied. There is nothing that I can complain. Especially if you are a solo traveler, I am pretty sure that you cannot find any other place in Rome which can beat Clarian for the price around 50 Euros. Each room has its own private bath and air conditioning, an LCD TV, a desk, a closet, a safety box, a mini fridge, a hair dryer and so on. As of June 2009, all the facilities are brand new and rooms are very clean. You can find more info on the webpage of the hotel which can be easily found by google. I can say that the photos on the webpage are very accurate.

The hotel has only four rooms and is run by a young couple with a cute baby living near the hotel. The wife or another lady comes to the hotel to serve breakfast and clean the room everyday. They are very friendly and fluent in English. It was quite a fun to chat with them.

Here are some more details that I think would be useful.
1. The wireless internet is free and is reasonably fast.
2. Breakfast is Italian and was more than enough for me: big croissant, dry bread, jam, butter, juice and cappuccino.
3. My room was faced to the street and the noise was not negligible. However closing the window reduces the noise significantly (although not perfect) and I had no problem during the night.
4. You will be given three keys - one for the main entrance to the building, one for the hotel and one for your room. It's almost like your house.
5. The surrounding area is quite pleasant to walk and there was no safety issue at all during my stay.
6. When I first arrived at the hotel it was a Sunday night. The door was closed but there was no response to the doorbell. I had to call the hotel to the phone number appearing on the internet. Then I was told to wait in other B&B at the same floor for about 10 minutes. So I suggest you keep the phone number with you in advance.

Overall I strongly recommend this B&B. I will definitely stay here again.